Testicular tissue characterization for gene expression analysis.

Antibody specifications.

Atypical histology and arrest of germ cell differentiation in trans women.

Panel A shows representative pictures of the lumen in adult (I), peripubertal (II), and prepubertal (III) controls, and an open (IV), half-open (V), or absent (VI) lumen in trans women. Graph VII shows the distribution of trans women over the three lumen categories. For each participant, the category was determined by the predominant pattern. Panel B illustrates the hyalinization status in adult (I), peripubertal (II), and prepubertal (III) controls, and the hyalinization stages that could be observed in the trans women: no (IV), mild (V), moderate (VI), or severe (VII) hyalinization. Graph VIII shows the distribution of trans women over the hyalinization stages. For each participant, the category was determined by the predominant pattern. Panel C demonstrates the different stages of germ cell differentiation that were present in trans women, namely MAGE-/BOLL-/CREM-/ACROSIN- (I), MAGE+/BOLL-/CREM-/ACROSIN- (II), MAGE+/BOLL+/CREM-/ACROSIN- (III), and MAGE+/BOLL+/CREM+/ACROSIN- (IV). No ACROSIN+ cells were detected. Graph V illustrates the distribution of trans women over the different stages of germ cell differentiation. Scale bars represent 200 µm. MAGE: melanoma-associated antigen A4, BOLL: boule homologue RNA-binding protein, CREM: cAMP-responsive element modulator.

Distinct ACTA2 expression patterns in the peritubular myoid cells of trans women.

Representative images of the ACTA2 expression patterns in adult (I), peripubertal (II) and prepubertal control (III), together with the “intact” (IV), “disconnected” (V), “interrupted” (VI), and “absent” (VII) patterns seen in trans women. Panel VIII illustrates the distribution of trans women across the four ACTA2 patterns. For each participant, the ACTA2 category was determined by the predominant pattern. Scale bars represent 200 µm. ACTA2: alpha-smooth muscle actin 2.

Partial Sertoli cell dedifferentiation in trans women.

Panel A illustrates the presence of SOX9 (general marker), AR (mature marker), and AMH (immature marker) within the seminiferous tubules of adult, peripubertal, and prepubertal control tissues, as well as in transgender tissue. Graph B shows the presence of the different AMH expression patterns in trans women. Additionally, graph C summarizes the percentage of trans women with only mature tubules, both mature and semi-mature tubules, only semi-mature tubules, and a combination of semi-mature and immature tubules. Graph C shows the presence of the different AMH expression patterns in trans women. Graph D illustrates the variation in Sertoli cell maturation across the different spermatogenic conditions. Scale bars represent 200 µm. Data are shown as mean + standard error. SOX9: SRY-box transcription factor 9, AR: androgen receptor, and AMH: Anti-Müllerian hormone.

Reduced Leydig cell maturity and functionality in trans women.

Panel A illustrates the presence of CYP11a1 (functional marker) and INSL3 (mature marker) within adult, peripubertal and prepubertal control tissues, as well as in transgender tissue. Graph B categorizes the Leydig cell functional maturity. Graph C shows the difference in functional maturity between the conditions of spermatogenesis. Scale bars represent 200 µm. Data are shown as mean + standard error. CYP11a1: cytochrome P45011, and INSL3: insulin-like factor 3.

Participant characteristics.

Transcriptome profile of control and transgender testicular tissue.

Projection on a two-dimensional PCA-based space of preprocessed sample data (A). The first dimension (dim. 1) represents around 90% of the variance in the data, segregating samples into two distinct groups: trans women/prepubertal and adult. Peripubertal samples were distributed across dim. 1. For each comparison (B), the number of genes above the background expression cutoff (2.032) is given (a total of 51065 were analyzed). The threshold for identifying DEGs was set to ≥2.0 fold-change (FC) and significance was determined using an adjusted p-value of ≤0.05 (B). The numbers at the bottom of the columns show upregulated (red arrow) and downregulated (blue arrow) DEGs. Heatmap representation of DEGs between the different types of testicular tissue analyzed (C). In total, 11661 DEGs were detected and grouped into 5 expression patterns (P1–P5) highlighting similarities and differences between the tissue groups. Each row represents a gene and each column a different donor. On the right side, GO terms enrichment analysis reveals biological processes (and some cellular components) significantly associated with each expression pattern. Next to each GO term, the number of associated genes and the corresponding p-value are provided.

Reference values for luteinizing hormone.

Reference values for follicle-stimulating hormone.

Reference values for testosterone.

Reference values for estradiol.

Reference values for anti-Müllerian hormone.

Reference values for Inhibin B.